Bacteria, Viruses, and Protists

Protists

How many species are in protist phyla, and what are some of their effects?

Biologists estimate that millions of species of protists could exist. The following lists, to date, the protist phyla, the estimated number of species, and some examples of the protists, such as in human disease (note: as more protists—and numbers of species in the various phyla—are found each year, these numbers will no doubt change):